ack/mach/powerpc/libem/sts.s
George Koehler 032bcffef6 In PowerPC libem, use the new features of our assembler.
The new features are the hi16/lo16 and ha16/lo16 syntax for
relocations, and the extended mnemonics like "blr".

Use ha16/lo16 to load some double floats with 2 instructions (lis/lfd)
instead of 3 (lis/ori/lfd).

Use the extended names for branches, comparisons, and bit rotations,
so I can more easily read the code.  The new names often encode the
same machine instructions as the old names, except in a few places
where I changed the instructions.

Stop using andi. when we don't need to set cr0.  In inn.s, I change
andi. to extrwi to extract the same bits.  In los.s and sts.s, I
change "andi. r3, r3, ~3" to "clrrwi r3, r3, 2".  This avoids setting
cr0 and also stops clearing the high 16 bits of r3.

In csa.s, los.s, sts.s, I change some comparisons and right shifts
from signed to unsigned (cmplw, cmplwi, srwi), because the sizes are
unsigned.  In inn.s, the right shift can be signed (sraw) or unsigned
(srw), but I use srw because we don't need the carry bit.

In fef8.s, I save an instruction by using rlwinm instead of addis/andc
to rlwinm to clear a field.  The code no longer kills r7.  In both
fef8.s and fif8.s, I remove the list of killed registers.

Also remove some whitespace from ends of lines.
2017-01-23 17:16:39 -05:00

51 lines
655 B
ArmAsm

.sect .text
! Stores a variable-sized structure from the stack.
!
! r3 = size
! r4 = address
.define .sts
.sts:
! These sizes are handled specially.
lwz r5, 0(sp)
cmplwi r3, 1
ble size1
cmplwi r3, 2
ble size2
cmplwi r3, 4
ble size4
! Variable-sized structure.
addi r3, r3, 3
clrrwi r3, r3, 2 ! align size
srwi r3, r3, 2 ! convert size to the number of words
mtspr ctr, r3
1:
lwz r5, 0(sp)
addi sp, sp, 4
stw r5, 0(r4)
addi r4, r4, 4
bdnz 1b ! decrement CTR, jump if non-zero
blr
size1:
stb r5, 0(r4)
b 1f
size2:
sth r5, 0(r4)
b 1f
size4:
stw r5, 0(r4)
1:
addi sp, sp, 4
blr